The subject matter disclosed herein relates to thrust bearings for use in turbomachinery or other rotating equipment.
Turbomachinery is found in aircraft engines, steam turbines, gas turbines, compressors, and various other applications. Differences in pressure created within a piece of turbomachinery result in axial thrust. For example, in a centrifugal compressor, pressure differences between the stages of the compressor create thrust along the axis of the rotor. Thrust bearings are frequently used to hold the rotor in place and allow it to rotate.
Oil-lubricated thrust bearings have typically been used in turbomachinery. In general, the higher the viscosity of the lubricating oil, the higher the load the bearing can support. However, oil-lubricated bearings can require a large number of ancillary parts, such as seals, due to the desire to keep the working fluid of the machine separate from the oil. Moreover, oil-lubricated bearings require complex lubrication systems that may include pumps, filters, external piping, heat exchangers, and sensors. The common requirement of separating the working fluid from oil limits the use of oil-lubricated bearings when considering hermetically sealed machines without ancillary sealing components. Furthermore, oil lubricants can have unfavorable reactions with process gasses, such as CO2.